The Complete Blood Count (CBC) is the most commonly performed clinical laboratory test in the United States and the world. A new technology for the CBC is proposed, which produces a monolayer of whole blood and uses computer image analysis. The system will be compact and much less expensive than current CBC instrumentation, which is based on multi-channel, multi-detector flow systems. A simple glass disposable slide will be used to prepare and analyze a stained monolayer from a drop of whole blood in seconds, using a novel, new method. The image analysis hardware will use a combination of darkfield and brightfield illumination, and spectral analysis. Software will be developed to acquire and analyze multiple images with different combinations of illumination type and color. Analysis of the images will provide all the conventional components of the Complete Blood Count (CBC) as well as a differential white blood cell count. An assessment of red blood cell and platelet morphology should also be feasible. The new system could be used in the clinical laboratory or directly in doctor's offices, creating a large new market opportunity. Applying the technology to veterinary medicine could expand its sales potential even further. Each year over 1.5 billion Complete Blood Count (CBC) tests are performed in the United States. The CBC is a critical component of patient diagnosis and treatment. There have been no fundamental improvements in the technology used to determine the CBC for over 20 years. This application proposes the development of a novel means of preparing and analyzing blood samples to determine the CBC and white blood cell differential count using computer imaging.